Aging skin is the result of more than just chronological age. Skin is exposed to various environmental stresses, such as UV rays, which cause free radicals to form in the skin. The degree of UV protection afforded by a composition is directly related to the amount and type of sunscreen actives present therein. The more sunscreen actives present, the greater the degree of UV protection. It is highly desirous for a sunscreen to offer a high degree of both UVA and UVB protection while being mild on the skin and cosmetically elegant. Mineral sunscreen actives, such as titanium dioxide and zinc oxide, are known to be efficient filters and especially mild on the skin. Consequently cosmetic companies seek to produce sunscreen formulations that utilize mineral sunscreen actives in place of organic filters. However, formulating sunscreens with inorganic filters/sunscreen actives presents a unique challenge because the inorganic filters have a tendency to re-agglomerate into large clusters. Due to this re-agglomeration tendency, although formulae with a high concentration of mineral actives achieve desired high PFA/SPF values, the formulae are often draggy and whitening, forming a thick residual layer on the skin.
Recently, there has been an explosion of metastable products on the market that promise lighter textures. However, these formulae rely on high loads of cyclosiloxanes to obtain fluidity and often greasy pigment dispersions to ensure efficacy. To thicken their formulae/stabilize their dispersions, they have relied upon traditional thickeners used in skin and sun care such as DryFlo, corn Starch, carbomers and Xanthum Gum.
It is an object of the present invention to provide a mineral sunscreen composition with high PFA/SPF properties that is stable and avoids re-agglomeration of sunscreen actives thereby providing a non-whitening and cosmetically elegant composition.